The percentage of recurring revenue retained from existing customers over a year, including expansion and churn.
Net Revenue Retention (NRR) measures how much recurring revenue you keep and grow from your existing customer base over a period, including upsell and expansion, minus downgrades and churn. NRR above 100% means the base grows even with zero new customers. A 15-point NRR spread can translate to roughly 5× the valuation multiple - which is why NRR is often called 'the new ARR' in SaaS.
